Fix trivial type-check errors in file_manager.

ui/file_manager/file_manager/foreground/js/ui/preview_panel.js

Index: ui/file_manager/file_manager/foreground/js/ui/preview_panel.js
diff --git a/ui/file_manager/file_manager/foreground/js/ui/preview_panel.js b/ui/file_manager/file_manager/foreground/js/ui/preview_panel.js
index 449bdcae2c37e79f56ffe27fed3fb55533d48828..8def6fbf4292138c7812b61d479f7b49e383b26a 100644
--- a/ui/file_manager/file_manager/foreground/js/ui/preview_panel.js
+++ b/ui/file_manager/file_manager/foreground/js/ui/preview_panel.js
@@ -6,7 +6,7 @@
 
 /**
  * PreviewPanel UI class.
- * @param {HTMLElement} element DOM Element of preview panel.
+ * @param {Element} element DOM Element of preview panel.
  * @param {PreviewPanel.VisibilityType} visibilityType Initial value of the
  *     visibility type.
  * @param {MetadataCache} metadataCache Metadata cache.
@@ -41,7 +41,7 @@ var PreviewPanel = function(element,
 
   /**
    * Dom element of the preview panel.
-   * @type {HTMLElement}
+   * @type {Element}
    * @private
    */
   this.element_ = element;
@@ -55,7 +55,7 @@ var PreviewPanel = function(element,
       volumeManager);
 
   /**
-   * @type {HTMLElement}
+   * @type {Element}
    * @private
    */
   this.summaryElement_ = element.querySelector('.preview-summary');
@@ -68,7 +68,7 @@ var PreviewPanel = function(element,
       this.summaryElement_.querySelector('.calculating-size'));
 
   /**
-   * @type {HTMLElement}
+   * @type {Element}
    * @private
    */
   this.previewText_ = element.querySelector('.preview-text');
@@ -78,7 +78,8 @@ var PreviewPanel = function(element,
    * @type {FileSelection}
    * @private
    */
-  this.selection_ = {entries: [], computeBytes: function() {}};
+  this.selection_ = /** @type {FileSelection} */
+      ({entries: [], computeBytes: function() {}});
 
   /**
    * Sequence value that is incremented by every selection update and is used to
@@ -319,13 +320,13 @@ PreviewPanel.prototype.onTransitionEnd_ = function(event) {
  *
  * This label shows dots and varying the number of dots every
  * CalculatingSizeLabel.PERIOD milliseconds.
- * @param {HTMLElement} element DOM element of the label.
+ * @param {Element} element DOM element of the label.
  * @constructor
  */
 PreviewPanel.CalculatingSizeLabel = function(element) {
   this.element_ = element;
   this.count_ = 0;
-  this.intervalID_ = null;
+  this.intervalID_ = 0;
   Object.seal(this);
 };
 
@@ -344,7 +345,7 @@ PreviewPanel.CalculatingSizeLabel.prototype = {
   set hidden(hidden) {
     this.element_.hidden = hidden;
     if (!hidden) {
-      if (this.intervalID_ != null)
+      if (this.intervalID_ !== 0)
         return;
       this.count_ = 2;
       this.intervalID_ =
@@ -352,10 +353,10 @@ PreviewPanel.CalculatingSizeLabel.prototype = {
                       PreviewPanel.CalculatingSizeLabel.PERIOD);
       this.onStep_();
     } else {
-      if (this.intervalID_ == null)
+      if (this.intervalID_ === 0)
         return;
       clearInterval(this.intervalID_);
-      this.intervalID_ = null;
+      this.intervalID_ = 0;
     }
   }
 };
@@ -376,7 +377,7 @@ PreviewPanel.CalculatingSizeLabel.prototype.onStep_ = function() {
 /**
  * Thumbnails on the preview panel.
  *
- * @param {HTMLElement} element DOM Element of thumbnail container.
+ * @param {Element} element DOM Element of thumbnail container.
  * @param {MetadataCache} metadataCache MetadataCache.
  * @param {VolumeManagerWrapper} volumeManager Volume manager instance.
  * @constructor
@@ -410,7 +411,7 @@ PreviewPanel.Thumbnails.ZOOMED_THUMBNAIL_SIZE = 200;
 PreviewPanel.Thumbnails.prototype = {
   /**
    * Sets entries to be displayed in the view.
-   * @param {Array.<Entry>} value Entries.
+   * @param {FileSelection} value Entries.
    */
   set selection(value) {
     this.sequence_++;
@@ -447,14 +448,14 @@ PreviewPanel.Thumbnails.prototype.loadThumbnails_ = function(selection) {
 
     // Load the image.
     if (entries[i]) {
-      FileGrid.decorateThumbnailBox(box,
-                                    entries[i],
-                                    this.metadataCache_,
-                                    this.volumeManager_,
-                                    ThumbnailLoader.FillMode.FILL,
-                                    FileGrid.ThumbnailQuality.LOW,
-                                    i == 0 && length == 1 &&
-                                        this.setZoomedImage_.bind(this));
+      FileGrid.decorateThumbnailBox(
+          box,
+          entries[i],
+          this.metadataCache_,
+          this.volumeManager_,
+          ThumbnailLoader.FillMode.FILL,
+          FileGrid.ThumbnailQuality.LOW,
+          i == 0 && length == 1 ? this.setZoomedImage_.bind(this) : undefined);
     }
 
     // Register the click handler.
@@ -470,11 +471,12 @@ PreviewPanel.Thumbnails.prototype.loadThumbnails_ = function(selection) {
  * Create the zoomed version of image and set it to the DOM element to show the
  * zoomed image.
  *
- * @param {Image} image Image to be source of the zoomed image.
- * @param {Object} transform Transformation to be applied to the image.
+ * @param {HTMLImageElement} image Image to be source of the zoomed image.
+ * @param {Object=} opt_transform Transformation to be applied to the image.
  * @private
  */
-PreviewPanel.Thumbnails.prototype.setZoomedImage_ = function(image, transform) {
+PreviewPanel.Thumbnails.prototype.setZoomedImage_ = function(image,
+                                                             opt_transform) {
   if (!image)
     return;
   var width = image.width || 0;
@@ -512,13 +514,14 @@ PreviewPanel.Thumbnails.prototype.setZoomedImage_ = function(image, transform) {
 
   var boxWidth = Math.max(PreviewPanel.Thumbnails.THUMBNAIL_SIZE, imageWidth);
   var boxHeight = Math.max(PreviewPanel.Thumbnails.THUMBNAIL_SIZE, imageHeight);
-  if (transform && transform.rotate90 % 2 == 1) {
+  if (opt_transform && opt_transform.rotate90 % 2 == 1) {
     var t = boxWidth;
     boxWidth = boxHeight;
     boxHeight = t;
   }
 
-  util.applyTransform(zoomedImage, transform);
+  if (opt_transform)
+    util.applyTransform(zoomedImage, opt_transform);
 
   var zoomedBox = this.element_.ownerDocument.createElement('div');
   zoomedBox.className = 'popup';